Field of the Invention
This invention relates to a method of manufacturing a weather strip. More particularly, the invention relates to a method of manufacturing a weatherstrip including the step of connecting a first extruded component and a second extruded component, each having surface treated portions and cut to a predetermined length, by means of a molded connecting portion (hereinafter referred to as a molded portion) which is molded by forcing molding material into a cavity defined by inserting and setting the two extruded components in a mold.
A conventional method of manufacturing a door glass-run (hereinafter referred to as a glass-run) which is a sort of weatherstrip will be described by way of example. A glass-run fitted to a front door D (FIG. 1) is shown in FIG. 2 in plan view, and in FIGS. 3 and 4 in sectional view. The conventional glass-run manufacturing method is carried out as follows:
Insert and set in a mold a first extruded component (an upper portion) 1 or 1A and a second extruded component (a lower portion) 3 or 3A, each having surface treated portions (formed by subjecting to slidability-adding treatment through urethane coating, for example) S and cut to a predetermined length, and force molding material into a cavity defined in the mold, whereby a molded portion 5 or 5A is molded whose sectional width and height are variable. Then, the individual glass slidable surfaces of the molded portion 5, 5A are subjected to slidability-adding treatment (S).
However, the size l.sub.1, l.sub.2 of the molded portion is fairly long (normally on the order of 25 to 30 cm), and the sectional shape of the molded portion is complicated as shown in FIGS. 2 through 4. Therefore, a large amount of molding material is required. Accordingly, the molding machine must be large and the molding process is limited to, for example, injection molding which requires that the molding material be fluid. Thus, the initial cost for manufacture increases, as do the required manhours for molding increases too.
Further, subjecting surface portions to slidability-adding treatment after molding is performed three-dimensionally on the large-sized glass-run which has a U-shaped glass slidable groove as shown in FIGS. 3 and 4. Accordingly, this surface treatment work is difficult and requires many man hours.